China Yields East Asia's Earliest Fossilized Frog

Chinese scientists announced that they have discovered the earliest frog fossils in Asia, whichthey believe would solve the riddles in life evolution.

����"Hundreds of Cretaceous amphibian fossils have been unearthed from a famous dinosaur fossil beds at Sihetun in western part of Liaoning province since 2000," said Wang Yuan, expert from the Chinese Academy of Sciences (CAS), "among them there is a rare fossilized frog dating back to 125 million years ago."

����The well-preserved specimen was then named "Sanyanlichan", documenting the earliest and sole definite discoglossid fossil in Asia, and the second fully articulated specimen of Mesozoic age known for the group, according to Wang.

����Wang, associate research fellow in the Institute of Vertebrate Paleontology and Paleoanthropology in CAS, said that the specimen's most prominent character is the nine presacral vertebrates, one more than any extant frogs, indicating the early devolvement of frogs.

����He said that the finding would provide important evidence for the study of amphibian evolution and biogeographic history. The study of amphibian is of remarkable significance because the animal is a linkage between aquatic and terraneous life forms, representing a great success in evolution.

����The family Discoglossidae, with "Sanyanlichan" as ancestor, is a group of primitive frogs that includes the popular midwife toad (Alytes), males of which carry eggs around their legs, and the fire-bellied toad (bombina), the ventral surface of which is brightly colored for aposematic display.

����Fossil beds in western Liaoning Province gains its fame by producing exceptionally well-preserved vertebrate fossils, including primitive birds, feathered dinosaurs, mammals and other important fossils.

����"The finding also contributes to detect pollution degree of environments by studying malformation rates of amphibian babies," said Wangyuan.

����According to Wang, the amphibians' fossils are difficult to be preserved for its gentle bones, vulnerable to bacilli and other breakage.

����In Mesozoic times, when dinosaurs thrived, western part of Liaoning is supposed to have a lot of water, and the eruption of volcano or suddenly deposits of muddy stream procured the formation of frog fossils the scientists unearthed today, experts said.